Integrate ETW with VLOG logging.

base/logging_win.cc

Index: base/logging_win.cc
===================================================================
--- base/logging_win.cc	(revision 65044)
+++ base/logging_win.cc	(working copy)
@@ -22,25 +22,31 @@
 LogEventProvider::LogEventProvider() : old_log_level_(LOG_NONE) {
 }
 
-bool LogEventProvider::LogMessage(int severity, const std::string& message) {
+bool LogEventProvider::LogMessage(logging::LogSeverity severity,
+    const char* file, int line, size_t message_start,
+    const std::string& message) {
   EtwEventLevel level = TRACE_LEVEL_NONE;
 
   // Convert the log severity to the most appropriate ETW trace level.
-  switch (severity) {
-    case LOG_INFO:
-      level = TRACE_LEVEL_INFORMATION;
-      break;
-    case LOG_WARNING:
-      level = TRACE_LEVEL_WARNING;
-      break;
-    case LOG_ERROR:
-    case LOG_ERROR_REPORT:
-      level = TRACE_LEVEL_ERROR;
-      break;
-    case LOG_FATAL:
-      level = TRACE_LEVEL_FATAL;
-      break;
-  };
+  if (severity >= 0) {
+    switch (severity) {
+      case LOG_INFO:
+        level = TRACE_LEVEL_INFORMATION;
+        break;
+      case LOG_WARNING:
+        level = TRACE_LEVEL_WARNING;
+        break;
+      case LOG_ERROR:
+      case LOG_ERROR_REPORT:
+        level = TRACE_LEVEL_ERROR;
+        break;
+      case LOG_FATAL:
+        level = TRACE_LEVEL_FATAL;
+        break;
+    }
+  } else {  // severity < 0 is VLOG verbosity levels.
+    level = TRACE_LEVEL_INFORMATION - severity;
+  }
 
   // Bail if we're not logging, not at that level,
   // or if we're post-atexit handling.
@@ -48,27 +54,43 @@
   if (provider == NULL || level > provider->enable_level())
     return false;
 
-  // And now log the event, with stack trace if one is
-  // requested per our enable flags.
-  if (provider->enable_flags() & ENABLE_STACK_TRACE_CAPTURE) {
+  // And now log the event.
+  if (provider->enable_flags() & ENABLE_LOG_MESSAGE_ONLY) {
+    EtwMofEvent<1> event(kLogEventId, LOG_MESSAGE, level);
+    event.SetField(0, message.length() + 1 - message_start,
+        message.c_str() + message_start);
+
+    provider->Log(event.get());
+  } else {
     const size_t kMaxBacktraceDepth = 32;
     void* backtrace[kMaxBacktraceDepth];
-    DWORD depth = CaptureStackBackTrace(2, kMaxBacktraceDepth, backtrace, NULL);
-    EtwMofEvent<3> event(kLogEventId, LOG_MESSAGE_WITH_STACKTRACE, level);
+    DWORD depth = 0;
 
+    // Capture a stack trace if one is requested.
+    // requested per our enable flags.
+    if (provider->enable_flags() & ENABLE_STACK_TRACE_CAPTURE)
+      depth = CaptureStackBackTrace(2, kMaxBacktraceDepth, backtrace, NULL);
+
+    EtwMofEvent<5> event(kLogEventId, LOG_MESSAGE_FULL, level);
+    if (file == NULL)
+      file = "";
+
+    // Add the stack trace.
     event.SetField(0, sizeof(depth), &depth);
     event.SetField(1, sizeof(backtrace[0]) * depth, &backtrace);
-    event.SetField(2, message.length() + 1, message.c_str());
+    // The line.
+    event.SetField(2, sizeof(line), &line);
+    // The file.
+    event.SetField(3, strlen(file) + 1, file);
+    // And finally the message.
+    event.SetField(4, message.length() + 1 - message_start,
+        message.c_str() + message_start);
 
     provider->Log(event.get());
-  } else {
-    EtwMofEvent<1> event(kLogEventId, LOG_MESSAGE, level);
-    event.SetField(0, message.length() + 1, message.c_str());
-    provider->Log(event.get());
   }
 
   // Don't increase verbosity in other log destinations.
-  if (severity >= provider->old_log_level_)
+  if (severity < provider->old_log_level_)
     return true;
 
   return false;
@@ -95,21 +117,17 @@
   // Convert the new trace level to a logging severity
   // and enable logging at that level.
   EtwEventLevel level = enable_level();
-  switch (level) {
-    case TRACE_LEVEL_NONE:
-    case TRACE_LEVEL_FATAL:
-      SetMinLogLevel(LOG_FATAL);
-      break;
-    case TRACE_LEVEL_ERROR:
-      SetMinLogLevel(LOG_ERROR);
-      break;
-    case TRACE_LEVEL_WARNING:
-      SetMinLogLevel(LOG_WARNING);
-      break;
-    case TRACE_LEVEL_INFORMATION:
-    case TRACE_LEVEL_VERBOSE:
-      SetMinLogLevel(LOG_INFO);
-      break;
+  if (level == TRACE_LEVEL_NONE || level == TRACE_LEVEL_FATAL) {
+    SetMinLogLevel(LOG_FATAL);
+  } else if (level == TRACE_LEVEL_ERROR) {
+    SetMinLogLevel(LOG_ERROR);
+  } else if (level == TRACE_LEVEL_WARNING) {
+    SetMinLogLevel(LOG_WARNING);
+  } else if (level == TRACE_LEVEL_INFORMATION) {
+    SetMinLogLevel(LOG_INFO);
+  } else if (level >= TRACE_LEVEL_VERBOSE) {
+    // Above INFO, we enable verbose levels with negative severities.
+    SetMinLogLevel(TRACE_LEVEL_INFORMATION - level);
   }
 }